Sound recording and reproducing machine



May 19, 1925.

H. A. ROGERS SOUND RECORDING AND REPRODUCING MACHINE Filed Sept. 19, 1924 Fig. i.

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" t'll/1111 rig Patented May 19, 1925.

UNITED STATES HAROLD ALFRED ROGERS, OF CARDIFF, WALES.

SOUND RECORDING AND REPRODUCING MACHINE.

Application filed September 1/0 aZZ whom it may concern:

Be it known that I, HAROLD Atrium Roenns, a subject of the King of Great Britain and Ireland, of 56 New Zealand Road, Cardiff, Vales, have invented certain new and useful Improvements in or Relating to Sound Recording and Reproducing Machines, of which the following is a specilication.

This invention consists of improvements in, or modifications of, the invention described and claimed in the specification of my earlier application Serial No. 689,744, which relates to a rolling speed control for sound recording and reproducing machines adapted to run at a variable speed wherein a rolling member makes contact directly or indirectly with the needle-track and is connected by a helical drive with a governor of the revolving weight type, the whole being mounted in a frame or partially enclosed in a box which is hinged horizontally and vertically to the sound box and connected by a guide rod to a pivot on the tone-arm standard or casing so that the rolling member, resting on the record, directly or indirectly through an intermediate band, adapts itself to inequalities in the record surface and to angular variations with the sound box maintaining its tangential alignment with each groove in the record.

According to the present invention, instead of the rolling speed control being hinged to the sound box, the guide rod to which it is connected is hinged to a fixed support and connected by links to the sound arm so that the said guide rod, and conse quently the rolling control, is caused to participate in the movement of the sound arm across the record. The rolling speed control is similar in other respects to the control described and claimed in specification of application Serial No. 689,744.

In the preferred construction according to'the present invention, the connection between the tonearm and the speed control consists of a. pair of guide rods or arms pivoted at, and radiating from, a common centre at or near the tone-arm pivot, the free end of one arm being attached to the speed control and the free end of theother arm to the tone-arm, the arms lying at opposite sides of the disc-record, and both of said arms being connected together near their pivot by a pair of hinged links the links, being attached at the point where they 19, 1924. Serial No. 738,626.

meet to a sliding block which is preferably, but not necessarily, spring controlled from the pivot of said arms or from a fixed point on the machine. In this way the traversing movement of the arm connected to the tonearm to or from the centre of the record is transmitted to, and imitated by, the arm connected to the speed. control in an equal or in an unequal ratio, according to the respective lengths and positions of said links, and the speed control is automatically kept at a distance from the centre of the record determined by that of the needle on the sound-box.

A practical embodiment of the invention is illustrated by the accompanying drawing wherein z- Fig. 1 is a plan showing a pair of pivoted guide rods or arms, of which the longer is attached to the speed control and the shorter to the tone-arm of a gramophone.

Fig. 2 is an elevation of a speed control with a connection to the pivoted arm.

Figure 3 is an enlarged section of the arm 1 or 2 which is preferably made arcuate in cross section for the sake of strength and rigidity.

Figure 4 is a perspective view of the clip 5, pivoted to the arm 2 and adapted to grip the tone arm.

Figure 5 is a vertical section through the links 7 and 8, sliding block 11, and guide rod 12.

Figure 6 is a cross section of the perforated pivot pin 4 with arms 1 and 2.

Figures 7 and 8 are respectively, an elevation and an underside view of the rod 12 and vertical spindle 14:.

Figure 9 is an elevational view partly in section of the supporting post for the guide arms.

Referring to the drawings, a pair of arms 1 and 2 are pivoted at, and radiate fronna common centre atfS, by means of a perforated pivot pin 4, the longer arm 1 having its free end slotted for convenience of adjusting the position of the speed control and the shorter arm 2 being fitted at its free end with a clip 5 pivoted to the arm and adapted to grip the tone-arm 6. A pair of links 7 and 8 are connected to the arms by pins 9 and 10 and are hingedly attached at the point where they meet to a sliding block 11 which is slidable on the rod 12 with the movement of the tone-arm 6, aided by the spring 13 (or other suitable spring) which surrounds the rod 1.2 between the pivot & and theblock 11. One end of the rod 12'is pivoted'to the end of the vertical spindle 1e shown in Fig. 9 on which is mounted the perforated pivot pin 4- which carries the arms 1 and 2, and the other end of the rod 12 is supported in a bracket 15 which is fixed to the gramophone cabinet. T he spindle 14, as shown in Fig. 9 is mounted pivotally at its lower end in a bracket 2 1 secured tothe-motor board, and is kept upright by a'flat spring 25 which normally bears against its'flatlowerend. lVhen-desired, the spindle 11 1 can be rocked backward onits pivot to permit rod 12 to be withdrawn from the bracket'lfi, in which 'position'ot' the parts the control can'be litted off the machine.

'Bythe arrangementshown the arm 2 and the sound box .16 are uniformly impelled inwardly, -i. .e., towards the centre of the record 17 by the decreasing diameter of the record track, and this traversing movement of the arm and the soundbox is transmitted to, and imitated by, the arm 1 connected to the speed control'in an equal or in an unequal ratio, according to the re spectivelengths and positions ot'the links 7 and 8,-and the speed control is automatically' kept at a distance from the centre of the recorddetermined hythat otthe needle on the sound box. Assuming that the links 7 and 8 are equal in length and are respectively connected to the arms land 2, at equal distances from the pivot 1 that the needle is in the groove when the periphery of the record and the contact wheel 18 of the control occupies the groove at the same distance from the centre ot' the disk but on opposite sides of the centre ot the record, the traversingmovement of arms 1 and 2 will' be equal and coincident atv all points, and linear record speed will be constant.

Fig. 2 shows a rolling speed'control with a rolling contact wheel 18 connected. at =19 to the arm 1, and provided. with the wormwheel 20 driving the governor spindle 21 and weights 22.

It is to beunderstoodthat variousm'odificationsof the basic idea of theinvention may be employed without departing from the scopeof the invention.

I claim 1.--A'speed control device for a sound recording and reproducing machine using disk'records and having a sound arm, comprising a pair of guide rods pivotally mounted at a common center adjacent'the axis-of oscillation of the sound arm and adapted to lie Eli- OPPOSliB sides of the center ot'the record, speed control *means carried by one guide rod and engageable withthe record, the other-guide rod bein'g connected to the sound arm, a block slidable along a line dividing the angle between said guide rods,

and links pivotally connecting said guide rods and block whereby movement of the sound arm toward the center of the record causes corresponding movement of the arm carrying the speed control means.

2. A-speedcontrolling device for a sound recording and reproducing machine using disk records andhaving a sound arm, comprising a pair of guide rods pivotally mounted at a common center adjacent the axis of oscillation of the sound arm and adapted to lie at opposite sides of thecenter o'f the record,-speedcontrol= means carried by a guide rod and engageable with the record, the other guide rod being connected to the sound-arm, a slide rod fixedly arranged in a line'dividing' the angle'between said guide rods, a block slidableiupon'said slide rod, and. links pivotally connecting said guide rods and block whereby movement of the soundarm toward the centerof-the record causes corresponding movement oftheiarm carrying the speed control means.

3. A speed controllingdevicetor a sound recording and reproducingmachine using disk recordsandhaving asound arm, comprising a pair of guide rodspivotally mounted at a common center adjacent the axis of oscillation of the-sound arnrand-adapted to'lie at-opposite sides of the center of the record, speed control means carried by a guide rod'and-engageable with the record, the-other guide-rod being connected to the sound arm, a sliderod fixedlyarranged in a line dividing the angle betweensaid guide rods, a block slidable upon said rod, and links pivotally connecting-said guide rods and-block whereby m'oveme'nt'ot the sound arnrtoward'the center-of the'record causes correspondingmovement ot' the arn'rcarrying the speedcontrol-means,saidlinks being constructed to provide lost motion at their pivotal connections with said guide rods.

4;. A- speed controllingdevice for a sound recording and reproducingmachine .using disk records and-having a sound arm, comprising apair of guide rods-pivotally-mounted at acommon center adjaceut theaxis of oscillation of the sound armand adapted to lie at opposite sides of the center o'fthe record, speed control "means carried by a guide rod and engageable with the record, the other guide rod .7 being connected:t0 the sound arm, a slide rod -fixedly arranged in a line dividing the angle between said guide rods, a block slidable 1 upon said slide rod, and links pivotally connecting saiduguide rods and'block whereby -n'1ove-ment ot' the sound armtoward the center ot-the-record causing correspending:movement of thearm carryingthe speed control means, said links being constructed to provide lost motion at their pivotal connections with said. guide rods, and a spring surroundingsaid slide rod and bearing against said block for assisting the convergent movements of said guide rods.

5. A speed control device for a sound recording and reproducing machine using disk records and having a sound arm, comprising a support, a normally upright post pivotally connected to said support arranged adjacent the axis of oscillation of said sound arm, a pair of guide rods pivotal- .ly mounted at a common center upon said post and adapted to lie at opposite sides of the center of the record, speed control means carried by one guide rod and engageable with the record, the other guide rod being connected to the sound arm, a slide rod carried by said post and arranged in a line dividing the angle between said guide rod, a keeper normally retaining the 'free end or said slide rod when the post is in upright position, a blockslidable upon said slide rod, links pivotally connecting said guide rods and block, a spring engaging said post for normally maintaining it in upright position, said post being foldable against the tension of said spring to withdraw the free end of said slide rod from said keeper.

In testimony whereof I have signed my name to this specification.

HAROLD ALFRED ROGERS. 

